Generation of microwave radiation in the tunneling junction of a scanning tunneling microscope

Abstract
Difference-frequency generation at 9 GHz and laser-light rectification was demonstrated in the tunneling junction of a scanning tunneling microscope (STM) using CO2 laser radiation. Simultaneous measurements of mixing signals and the current-voltage (I-V) characteristics of the STM show that the mixing process occurs at the nonlinearity of the static I-V curve.